Systems for changing and inserting tools into or presenting tools at a machine tool and tool magazines for provisioning tools of a machine tool are known in various configurations from the prior art. Tool changing systems are used in milling machining systems, for example, to reduce the idle time of the respective processing machine, for example what is known as chip-to-chip time.
By means of tool changing systems of this type, tools are changed over, as required, from the tool magazine to a machining spindle of a machine tool, and vice versa. If appropriate, this takes place in a fully automated and program-controlled manner. For this purpose, the tool magazines accommodate a plurality of tools for the provisioning thereof and also comprise a manipulator for removing the tools from the magazine, said manipulator also being able to deliver the tools to a machine tool.
In this respect, two fundamental types of tool magazine in particular are known from the prior art which differ from one another in that either the tools are stored in a stationary, unmovable tool mount and a movable manipulator travels to the storage position of the tool to remove the tool therefrom by means of a removal device, or the receiving means for storing or receiving the tools is moved to a predetermined removal position in which the required tool is removed by the removal device of the stationary manipulator.
For example, chain magazines for machine tools having a rigid manipulator are known from the prior art, for example from DE 39 05 780 C1 and DE 10 2005 052353 A1. Chain magazines of this type comprise a chain which comprises along its course a plurality of receiving means or receiving portions for receiving tools, the chain being at least partly guided along a guide rail.
However, for the flexible machining of workpieces in modern machining centres, it is necessary in particular to provide a large number of different tools in one tool magazine and the problem arises in the case of the chain magazines described above that in order to store a large number of tools, either a plurality of chains or chain magazines has to be provided, or unfavourably long chains have to be provided. This means that a large set-up area is required for the chain magazine, and furthermore long tool provision times possibly arise in the case of chain magazines if a tool which is accommodated in the chain of the magazine at a distance from the manipulator is to be removed from the magazine.
The prior art also discloses rack magazines having rigid receiving means and a controllable removal device for removing the tools, described for example in DE 10 334 346 A1.
However, rack magazines of the prior art suffer from the problem that for storing a large number of different tools, subject to the tool provisioning and the control possibilities by the removal device of a manipulator, long tool provision times possibly arise and, in the same way, large set-up areas for the rack magazine are required.
DE 10 2004 028 151 A1 discloses a storage arrangement for processing machines with superimposed storage trays, on the lower side of which tool mounts are attached which are arranged in the shape of a circle and from which tools can be removed by a movable gripper arm. The gripper arm removes the tools in a direction vertical to the mounted tool axis and radially inwards. A tool magazine of a similar construction is described in DE 41 16 091 C1. In this case as well, the tool mounts are arranged in a circle and are removed radially inwards by a changing device arranged centrally to the arc of the circle. Likewise, DE 10 2009 008 647 A1 describes a tool changing system in which the tools are mounted inside the tool magazine on different planes in storage compartments which are arranged along an arc of a circle.
U.S. Pat. No. 4,394,908 A discloses a tool magazine in which tools are mounted along the circumference of two circular receiving discs arranged one above the other in the radial direction. The tools are stored in receiving containers, the receiving containers and the tools of the upper disc being tilted with respect to the receiving containers and the tools of the lower disc. A disadvantage of this tool magazine is that in order to remove a tool from the upper disc, the appropriate container must firstly be lowered into a free position of the lower disc, because the tool changer can only remove the tools in a predetermined changing position. This increases the tool changing times. Furthermore, the construction mechanism only functions with a maximum of two superimposed discs and does not scale thereto. Thus, the receiving space for tools is restricted.
On the other hand, DE 197 08 096 A1 discloses a machining centre comprising a tool store from which the tools are delivered directly to the working spindle radially outwards without the provision of a manipulator which firstly removes the tools from the magazine and then delivers them to the working spindle.
Similarly to chain magazines, circular-type or column-type tool magazines of this kind can store a large number of tools with faster access times to the tools compared to rack magazines. However, rack magazines still have to be frequently used in practice if, due to the restricted positioning space next to a machine tool, only one narrow rack magazine can be used.
US 2007/0 167 303 A1 discloses a tool magazine in which the tools are mounted displaceably along an arc of a circle and the tools are arranged in a plane perpendicular to a floor space. Two tools in each case can be stored in a double mount along the circular circumference. A disadvantage of this tool magazine is presented by the long tool changing times, because tools on the side opposite the tool changer can only be changed by repeated alternating rotational movements of the wheel magazine and travel movements of the manipulator. Furthermore, the receiving capacity is restricted because the described tool change can only be implemented for a single wheel magazine.